Developmental time pattern of Thanatophilus sinuatus at different constant and variable temperatures

As a forensically important species, Thanatophilus sinuatus (Fabricius, 1775) (Coleoptera: Staphylinidae) is often active and widely distributed on animal and human carcasses. Although there is developmental data available for this species under small-group feeding conditions, there is still a lack of data on the developmental time of this species under aggregate feeding conditions, focusing on each developmental stage. Also, there are no studies on the development of this species under variable temperatures. Thus, this study focused on the aggregate rearing of T. sinuatus in China at seven constant temperatures and three variable temperatures from 16 to 34 °C, recording the developmental duration and accumulated degree days (ADD) of each developmental stage in detail. Additionally, body length, head capsule width and mesonotum width were measured at different times, and the survival rate was calculated for each stage. Based on the above data, an isomorphen diagram, the linear thermal summation models, the curvilinear Optim SSI models, and a survival curve were established and the head capsule width and mesonotum width were cluster analyzed to identify between instars. In addition, differences in total developmental time between constant and variable temperatures under the same mean temperature were compared to provide more comprehensive developmental data for estimating postmortem interval (PMI) using this species.